The invention refers to an inner conductor contact, and in particular to an inner conductor contact for connecting one end of a braided inner conductor of a coaxial cable with one end of an inner conductor of a coaxial plug, with the inner cable conductor enclosing a core.
Conventional coaxial cables generally include a massive inner conductor, or an inner conductor made of litz wires or strands when high flexibility is demanded. Also known are coaxial cables which have an inner conductor woven about a core. The latter coaxial cables are generally used when transmitting high powers via a flexible cable and/or when requesting low attenuation because in this case only cables of great diameter are suitable. An inner conductor of litz wire would not be sufficiently flexible and too lossy in such circumstances.
In coaxial cables with braided inner conductor woven about a core, the latter is made either of a massive round plastic cord or of a stable plastic tube. Sometimes, also a complete coaxial cable is used as the inner conductor, however without insulating outer sheath so that the braided outer conductor of such a conventional coaxial cable (correspondingly smaller diameter) serves as inner conductor which is surrounded by the cable dielectric upon which the braided outer conductor is applied which in turn is enclosed by the insulating outer sheath.
A flexible coaxial cable of this type has the drawback that the contact i.e. electric (and mechanical) connection of the inner cable conductor with the cable-side part of the inner plug conductor is very difficult to accomplish. To date, either the inner cable conductor was soldered with the inner plug conductor or the connection was done by means of a collet chuck type device which is externally clamped upon the braided inner cable conductor. This type of connection represents, however, an area of electric discontinuity because the diameter of the collet chuck exceeds the diameter of the inner cable conductor. Even though it may be feasible, e.g. by increasing the diameter of the outer conductor, to essentially keep the characteristic impedance in the contact area constant so that the reflection in the contact area is kept within an acceptable range, the diametric jump still decreases the cutoff frequency of the arrangement of cable and plug compared to the cutoff frequency of the cable.